gistfile1.sql

SELECT
  s.name
FROM
  seq_region s
INNER JOIN
  seq_region_attrib USING (seq_region_id)
INNER JOIN
  coord_system c USING (coord_system_id)
LEFT JOIN
  assembly ON seq_region_id = asm_seq_region_id
WHERE 
  attrib_type_id = 6
AND
  c.attrib NOT LIKE '%sequence_level%'
AND
  asm_seq_region_id IS NULL
;